The Sterling Family Trust, which owns the team with Donald and his wife Shelly having a 50 percent share each, contains a stipulation pertaining to the mental well-being of the two trustees.

Experts deemed that Donald Sterling failed to reach the required mental standards, meaning that he does not have the authority to stop the sale and his wife has sole decision-making over the franchise, according to the source.

Sterling had vowed that he would never put the Clippers up for sale, even though the NBA said it planned to force him to sell the team following his racist remarks in a secretly-recorded phone conversation with a former girlfriend, model V. Stiviano.

Last week, however, Sterling gave his wife permission in writing to dispose of the team. But soon after, his attorney said that Sterling had a change of mind and planned to fight the NBA, which banned him for life from attending Clippers games and also fined him $2.5 million.

Shelly Sterling reached an agreement Thursday to sell the Clippers to former Microsoft CEO Steve Ballmer for $2 billion. Donald Sterling paid $12 million for the team in 1981.

"Shelly Sterling was acting under her authority as the sole trustee of the Sterling Family Trust which owns the Clippers," said a press release from her representatives, according to USA Today.

And Shelly Sterling said in the statement, "I am delighted that we are selling the team to Steve, who will be a terrific owner. We have worked for 33 years to build the Clippers into a premiere NBA franchise. I am confident that Steve will take the team to new levels of success."

Ballmer said in his statement, "I love basketball. And I intend to do everything in my power to ensure that the Clippers continue to win – and win big – in Los Angeles."